Gkeorge w



Dec. 1 1925.

G. W. HEESE GALVANIC CELL OF THE COPPER OXIDE TYPE Filed-May 27. 1924Patented Dec. l, i925.

as is GEORGE W. HEISE, 01* BAYSEDE, NEV] 1 0E3 5, AElfiIGHGB TONATTOE'AI, CARBON COM- PANY, INTI, A GDEPOEATION EIIEVV' YORK.

GALVANIC CELL 0 THE COPPER-Q3511)? Application filed May 27, 1924..

cells of the soluble metal-caustic alkalidepolarizing oxide type,especially copper oxide cells. A primary purpose of the inven tion is toprevent the adverse effect of dissolved copper. This is preferablyaccomplished by fixing the dissolved copper in the form of compoundshaving no substantial detrimental action in the cell.

To this end I have devised improved coatings, wrappings, or the like,which are interposed between the copper oxide and the causticelectrolyte. These may have the dual function of fixing dissolved copperand of preventing the escape of copper oxide particles. Alternatively,suitable materials may be added to the electrolyte to react ivith copperin solution. The invention includes other novel and advantageousfeatures, which will appear from the following description.

It has heretofore been proposed to secure a paper wrapping or lining bymeans of an adhesive to copper oxide containers. The quently the actionof the caustic electrolyte loosens the paper and causes it to break awayfrom the container. In the prior processes referred to, this has notbeen con sidered an objection, because the only func tion sought'fromthe paper was that of retaining the oxide during the period before thefilled container was put into service.

I have discovered that a layer of cellulosic material of special type,or its equivalent, has an additional function of great importance whichis operative throughout the service life of the cell. This function, asnoted above, is the retention of dissolved copper. My experiments 'have'demonstrated that copper oxide is dissolved from the depolarizer by theelectrolyte and that the copper in solution is decidedly detri- SerialNo. 716,267.

mental. Copper appears to be deposited. upon the-zinc, causing wastefullocal action.

T have discovered, further, that the dissolved copper reacts withcertain materials to form compounds harmless to the cell. Among thesematerials are cellulosic compounds, for example wood. pulp and starch,and nitrogenous bodies of the type of gluten. In the case of wood pulpit seems probable that cellulose hydrates are formed, and that thesehydrates combine with the dissolved copper compounds to form a gelinsoluble in the alkali electrolyte. The invention is of course in noway dependent upon the theory of reaction.

l/Vith reference to the use of starch, I am aware that this material hasbeen employed as a gelatinizing agent for caustic electro lyte. For thepurposes of the present invention, the quantity of starch required isfar lower than that heretofore used.

In View of the facts stated, it is highly desirable to provide permanentcoating or lining which can be depended upon to pre vent dissolvedcopper from pa sing}; beyond the confines of the depolarizing: body. Thave attained this object, in one embodiment of the invention, byforming a paper coating directly upon the copper oxide element or thecontainer in which the copper oxide is to be placed.

It is preferred to form the paper coating in the following manner:Cellulosic material, preferably wood pulp such as is ordinarily used inpaper making, is beaten up with sufficient caustic alkali solution toform a gelatinous or pasty mass. This may be applied to the containersor coherent bodies of copper oxide and on drying will form a permanentlyadherent coating. When containers are used the depolarizer may 'beplaced therein as usual. If the depolarizer is to be tamped in underconsiderable pressure, it is desirable to provide a removable supportingsleeve adjacent to the container wall to prevent rupture of the coatingor lining.

The strength of the caustic solution used to gelatinize the wood pulpsuspension may be varied widely. A 2% aqueous solution iii of sodiumhydroxide may be used with advantage. Less than 0.7% alkali does notordinarily give good results. Solutions stronger than 2% areadvantageous in causticizing the pulp, but ordinarily give a productwhich is difficult to use. The retained caustic in such case frequentlymakes the pulp hygroscopic and corrosive when applied to metalcontainers. These difficulties may be avoided, however, by neutralizingthe greater portion of the alkali prior to the papering operation. Othergelatinizing agents, for example zinc chlorid, may be used instead of analkali metal hydroxide. The causticized product may be applied invarious ways either to sheet metal, finished containers, or coherentdepolarizing bodies. It may be spread or brushed on, or may be sprayed.The appearance of the containers may be improved by floating a thinsuspension of the pulp over a rough first coat of thick pulp.

While causticized wood pulp is generally preferred, other forms ofcellulosic material or its equivalent may be used. For example, thedepolarizing bodics may be coated with an adhesive and rolled in woodfiber to form a surface layer.

For illustrative applications of the present invention, reference is tobe made to the accompanying drawing, in which:

Fig. l is a vertical section through a cell provided with a perforateddepolarizer container having a paper coating;

Fig. 2 is a perspective view of a metal blank with a similar coating;and

Fig. 3 is a perspective view of a papercoated, agglomerated mass ofcopper oxide, the coating being partly broken away.

In the drawing, reference numeral 1 denotes a perforated containersuspended by rod 2 from cover 3 and immersed in cautic alkalielectrolyte 4. The illustration shows a copper oxide cell of acommerical type. The invention may of course be applied to other kindsof cells.

The container 1 is covered with a. layer of cellulosic material 5, orequivalent substance. exterior coating, as shown, and by the proc esspreviously described. It may, however, be applied as a lining, or maymerely fill the perforations.

While the cellulosic material may be applied to finished containers,there is-considerable advantage in coating perforated sheet metal priorto shaping it. As shown in Fig. 2, a layer 6 of causticized wood pulpmay be applied to a perforated metallic sheet 7 adapted for use inmaking up containers. The layer 6 does not interfere with the shaping ofthe metal nor become detached during that process.

As shown in Fig. 8, cellulosic material 8 may be applied to anagglomerated mass of This is preferably applied as an.

1,5ea,eeo

copper oxide 9. Various other applications of the material may be made.7

Unlike paper secured to the container by an adhesive, the paper formedin situ as de 'cribed does not become detached even after long immersionin electrolyte. It has, moreover, a much greater power of fixingdissolved copper than has the paper heretofore used. This is probablydue to the fact that it is applied in causticized state.

I prefer to use the new form of paper coating in all cases, but it iswithin the scope of the invention to apply a cellulosic coating of anysuitable kind to coherent bodies of copper oxide. So far as I am aware,cellulosic material has heretofore been used in copper oxide cells onlyin connection with containers for the purpose of obstructingperforations, or for gelatinizing the electrolyte, as referred to aboveThe present invention attains the novel result of preventing copper frompassing into liquid GlGCtI'O. lyte from coherent depolarizing bodies. 1The invention includes further the improved cellulosic coatingdescribed, as applied either to coherent depolarizers,= containers, orin other suitable ways.

I do not claim herein the coating or lining of copper oxide containerswith paper in preformed sheets, the filling of the perforations in suchcontainers with cellulosic ma.- terial, or broadly the use of proteins,gums, and resins in the electrolyte. Such subject matter is describedand claimed respectivel in applications Serial Nos. 610,84t, filedJanuary 5, 1923, 606,520, filed December 12, 1922, and 619,464l, filedFebruary 16, 1923, in each of which I am a co-inventer.

I claim:

1. In a galvanic cell with copper oxide depolarizer and fluid causticelectrolyte, a material adapted to chemically fix dissolved copper andoperative-1y disposed with respect to the depolarizer.

2. In a galvaniccell with copper oxide dcpolarizer and causticelectrolyte, a coating upon the depolarizer and adapted to chemicallyfix dissolved copper.

3. A coherent copper oxide depolarizer having thereon a coating ofmaterial adapted to chemically fix dissolved copper.

f. A copper oxide depolarizing body having thereon a coating ofcausticized cellulosic material.

5. A copper oxide depolarizing body having thereon a coating ofcausticized wood pulp.

6. A copper oxide container comprising perforated sheet metal havingthereon a coating of causticized cellulosic material.

7.,Process of preventing the detrimental effect of dissolved copper influid caustic electrolyte, comprising utilizing in the cell a materialadapted to chemically fix such copper in harmless form. r

8. Process of coating copper oxide deperforated sheet metal adapted tobe shaped 1 polarizing bodies, comprising applying into copper oxidecontainers, comprising thereto a layer of causticized celhdosicinaapplying thereto causticized Wood pulp. terial. 11. Process ofcoating copper oxide con- 9. Process of forming an adherent papertainers, comprising distributing thereon coating on copper oxidedepolarizing bodies, causticized cellulosic material adapted to 15comprising applying thereto gelatinous form a paper-like layer.causticized Wood pulp. In testimony whereof, I affix my signature.

10. Process of forming a surface layer on GEORGE W. I-IEISE.

